At present, more and more electronic devices are equipped with touch screens, for example, information inquiring machine in a hall of a public place, computers, mobile phones used by users in daily life and work, and the like. In this way, the user can operate the electronic device just by touching icons on the touch screen with a finger, so that there is no need on keyboard and mouse operations, thereby making the human-computer interaction simpler. In order to better meet the requirement of user, the touch screen is typically provided with a pressure sensor for detecting a magnitude of a touch pressure when the user touches the touch screen.
Bridge strain sensor is a kind of pressure sensor capable of detecting the magnitude of the touch pressure. The bridge strain sensor calculates the magnitude of the touch pressure by detecting an in-plane deformation caused by a z-direction strain and measuring a change in a resistance of the sensor.
In a related art, a display panel is provided with a plurality of bridge strain sensors. Each stain sensor needs to be provided an input voltage via a wire. In order to reduce the number of wires, the strain sensors may share a voltage input wire. However, since the wire has a certain resistance, the stain sensors connected in parallel may receive different disturbed input voltages when the stain sensors share the voltage input wire. Especially, the received input voltage of the strain sensor that is remote from the input voltage is much smaller than the input voltage supplied by a voltage input device. As a result, the pressure detection sensitivity is affected.